- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Research on high resolution fiber Bragg grating sensing technology based on high speed parallel sampling
摘要： The high resolution fiber Bragg sensing system based on high speed parallel sampling technology is proposed. According to the Rayleigh criterion, it is generally believed that the number of the measured data of the fiber grating reflection spectrum is limited to the resolution of the wavelength measurement device. So, in order to achieve high spectral resolution, high resolution wavelength measurement devices, at the same time, to achieve small variations of the transmission wavelength of the Fabry–Perot (FP) filter, the high bit digital-to-analog converter (DAC) was adopted to generates small step drive voltages, these will greatly increase the cost of the system. However, in this paper, the fiber Bragg sensing system with the low resolution FP filter and low bit DAC achieves the high resolution wavelength measurement by using the high speed parallel sampling. In addition, the resolution of wavelength in fiber grating sensing system is analyzed theoretically.
关键词： Parallel sampling technology,Wavelength resolution,Fiber Bragg grating,Optical fiber sensing
更新于2025-09-10 09:29:36
-
[IEEE 2018 Condition Monitoring and Diagnosis (CMD) - Perth, WA (2018.9.23-2018.9.26)] 2018 Condition Monitoring and Diagnosis (CMD) - Usability of fiber Bragg grating sensors for the fatigue life monitoring of overhead transmission lines
摘要： Fretting fatigue of transmission lines, caused by Aeolian vibration, always leads to catastrophic failure of conductors. The fatigue life monitoring of overhead transmission lines is an effective method to foresee strands broken of the conductor. Fatigue severity is usually expressed by alternating bending stress which occurs in the vicinity of suspension clamps during vibration. Given that it is hard to measure the fatigue stress directly, according to IEEE, alternating bending amplitude is recommended as a substitute measured parameter for fatigue life. In this paper, an on-line monitoring system based on a fiber- optic acceleration sensor is designed to analyze the fatigue life of overhead transmission lines in Aeolian vibration surveillance. Considering its superior performance of anti-electromagnetic interference, Fiber Bragg Grating (FBG) sensor is used to measure alternating bending amplitude of overhead transmission lines. And a Cumulative Fatigue Damage (CFD) method, which is based on alternating bending amplitude for vibration and the Stress-Cycle (S-N) curves, is proposed to calculate the fatigue life of overhead transmission lines. A case study of the one-month measurement data of Aeolian vibration for 1000kV Ultra-High Voltage (UHV) transmission lines is presented. Then an on-line monitoring system based on a fiber-optic acceleration sensor is designed to analyze the fatigue life of overhead transmission lines in Aeolian vibration surveillance.
关键词： Fretting fatigue,Aeolian vibration,life prediction,fiber Bragg grating
更新于2025-09-09 09:28:46
-
Simultaneous measurement of strain, temperature and refractive index based on a fiber Bragg grating and an in-line Mach–Zehnder interferometer
摘要： A simple sensor for simultaneous measurement of strain, temperature and refractive index (RI) is proposed and demonstrated. The sensor is based on a fiber Bragg grating (FBG) combined with an in-line Mach-Zehnder interferometer (MZI). MZI is formed by introducing a section of thinned core fiber (TCF) between two segments of multimode fiber (MMF). The two MMFs act as couplers that can excite high-order modes and recouple core mode and high-order modes into lead-out SMF, the function of this structure is to form inter-modes interference. The maximum interference fringe visibility exceed 20 dB. By monitoring the wavelength shifts of FBG and interference dips, simultaneous measurement of strain, temperature and RI can be achieved. The experimental results show that the maximum sensitivity of the sensor for strain, temperature and RI are -2.14 pm/με, 35.2 pm/°C and 32.93 nm/RIU, respectively. The proposed sensor has the advantages of easy fabrication, high fringe visibility and high sensitivities. Therefore, it has potential applications in multi-parameters simultaneous measurement.
关键词： Temperature,Refractive index,Mach-Zehnder interferometer,Strain,Fiber Bragg grating
更新于2025-09-09 09:28:46
-
A Novel Temperature-Insensitive Hydrostatic Liquid Level Sensor Using Chirped FBG
摘要： A novel half-bonded chirped fibre Bragg grating (CFBG) on a natural rubber diaphragm has been proposed to enhance the sensitivity and to compensate the temperature effects of a hydrostatic liquid level sensor. This innovative fabrication method resulted in the narrowing of the bandwidth with the hydrostatic pressure sensitivity recorded at -253 pm/kPa and water column sensitivity at -0.0253 nm/cm. The bandwidth modulation measurement was insensitive to temperature variations, when compared to centre wavelength modulation measurement. Furthermore, the proposed hydrostatic liquid level sensor is compatible with low cost photodetector.
关键词： temperature compensation,liquid level,hydrostatic pressure,Chirped fibre Bragg grating
更新于2025-09-09 09:28:46
-
[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Towards Finger Motion Capture System Using FBG Sensors
摘要： This paper introduces a novel finger motion capture system using FBG (fiber Bragg grating) optical sensors. We develop two types of sensors to seamlessly reconstruct finger motion from strains induced in the FBGs. First, the shape sensor incorporates three optical fibers with multiple FBGs to reconstruct the position and orientation of a finger joint in 3D. In addition, the angle sensor is designed to measure the high curvature of bending on the finger joints. By deploying the two types of sensors on the fingers, we can reconstruct various finger motion in real time without drift over time. The accuracies of the fabricated FBG sensors are evaluated, resulting in an average error of 1.49 mm for the shape sensor at the distal tip (1.9% for the full length of the sensor) and 0.21° error for the angle sensor. We finally demonstrate finger motion tracking with the FBG sensors in real time, while measuring the multi-DOF motion at the carpometacarpal joint of the thumb and also the high curvatures of bending motion at the metacarpophalangeal and interphalangeal joints of the thumb and the index finger.
关键词： optical sensors,shape sensor,angle sensor,FBG,fiber Bragg grating,finger motion capture
更新于2025-09-09 09:28:46
-
An ultrasonic sensor composed of a fiber Bragg grating with an air bubble for underwater object detection
摘要： We present and experimentally demonstrate a novel optical fiber ultrasonic sensor composed of a fiber Bragg grating (FBG) with an air bubble for underwater object detection. The air bubble is formed by splicing etched FBG and single mode fiber (SMF) with taper-shaped holes. And because of the corrosive action, the diameters of FBG and SMF reduces from 125 μm to dozens of micrometers, which will be conducive to improving the sensor's performances. The experiment results indicate that the sensor has high voltage responses of 6.3 V and 7.1 V to the continuous and pulse ultrasonic wave (UW) at 1 MHz and could be used for underwater objects imaging with high signal-to-noise ratio (SNR). Subsequently, the environmental temperature will not influence ultrasonic measurements using the sensor on account of the low temperature sensitivity of 19.5 pm/°C.
关键词： Ultrasonic sensor,Fibre Bragg grating,Fibre-optic sensor,Underwater object detection
更新于2025-09-09 09:28:46
-
A real-time impact detection and diagnosis system of catenary using measured strains by fibre Bragg grating sensors
摘要： This paper describes an impact detection system using strain signals based on fibre optic sensors(FBG) for the real-time monitoring of the catenary system. The proposed detection system consists of three subsystems: a measuring system, a data processing and analysis system, and a status display and data access system. Because the strain signals obey the normal distribution, to monitor the catenary system in real time, a novel method that combines mobile standard deviation with the mobile Pauta criterion is proposed to distinguish real impact from the strain signal background. The use of this adaptive judging method reduces the misjudgment rate of impacts and improves the impact recognition accuracy. These impacts can be identified by the data analysis system, which provides impact location and their causes using the features of the catenary system. This method can simplify the detection system compared with the traditional location method. An application to a commercial metro line system indicated that the impacts on the catenary system were main caused by overlaps, expansion joints or steady arms, and were verified by correspondence with the floor plan of the catenary and manual inspection results. These results verified the reliability and effectiveness of the proposed impact detection system.
关键词： catenary,real-time monitoring,fibre Bragg grating,Impact detection,fault diagnosis
更新于2025-09-09 09:28:46
-
Radiation-Induced Effects on Fiber Bragg Gratings inscribed in Highly Birefringent Photonic Crystal Fiber
摘要： The Fiber Bragg Gratings (FBGs) inside Photonic Crystal Fibers having high fiber birefringence, such as in PCF with butterfly shape microstructure, are characterized by two Bragg peaks. The spectral distance between these two peaks is not affected by a change of temperature or by a longitudinally applied strain, but this spectral separation evolves when the sensor is subjected to a transversal strain. This makes such FBGs inscribed in highly birefringent PCFs very interesting for structural health monitoring of civil structures, as well as for operation in harsh environments such as the ones associated with the nuclear industry. In this work, we monitor the Radiation-Induced Bragg Wavelength Shift (RI-BWS) of the punctual sensor and the Radiation-Induced Attenuation (RIA) in the fiber used for its inscription up to a dose of 1.5 MGy(SiO2). Even if we observe a RI-BWS for both Bragg peaks, the spectral distance between them only slightly evolves, of less than 10 pm. These gratings are then very promising sensors for the structural health monitoring of nuclear facilities.
关键词： radiation effects,Fiber Bragg Grating,pressure sensors,Photonic Crystal Fiber
更新于2025-09-09 09:28:46
-
High-Speed and High-Resolution Interrogation of a Strain and Temperature Random Grating Sensor
摘要： High-speed and high-resolution interrogation of a random fiber grating sensor based on spectral shaping and wavelength-to-time (SS-WTT) mapping, and pulse compression for simultaneous measurement of strain and temperature is proposed and demonstrated. In the proposed system, an ultrashort pulse is spectrum shaped by a high-birefringence (Hi-Bi) random grating (HBRG) to generate two orthogonally polarized spectra with a wavelength difference determined by the birefringence of the HBRG, which are then fed to a dispersive optical loop in which a linearly chirped fiber Bragg grating (LCFBG) is incorporated, to perform linear WTT mapping, to generate two temporally separated optical pulses, which are converted to two random electrical waveforms at a photodetector). Random pulse compression is then performed to increase the interrogation resolution. By measuring the time shifts of the temporally compressed pulses, the strain and temperature information is retrieved. An experiment is performed. The experimental results show that the proposed random grating sensor and its interrogation system can provide a strain and temperature resolution of 7.1 με and 0.79 °C at an ultrahigh speed of 20 MHz.
关键词： linearly chirped fiber Bragg grating,Fiber Bragg grating,interrogation,sensor
更新于2025-09-04 15:30:14
-
Temperature-independent refractive index sensor based on fiber Bragg grating and spherical-shape structure
摘要： A fiber-optic refractive index (RI) sensor consisting of a fiber Bragg grating (FBG) spliced in downstream of a spherical-shape structure in a single-mode fiber (SMF) is proposed and experimentally demonstrated. The cladding modes with different effective refractive indices can be efficiently excited by the spherical-shape structure. By measuring the difference of the wavelength shifts between the reflected cladding Bragg mode and the core mode, we have achieved a maximum sensitivity of 2.87 nm/RIU with range of the RI from 1.357 to 1.458. When the temperature changes from 25 °C to 225 °C, the relative wavelength shift between the cladding mode and the core mode has no significant changes, which indicates that this fiber-optic sensor allows for temperature-independent RI measurement.
关键词： Refractive index sensor,Temperature-independent,Spherical-shape structure,Fiber Bragg grating
更新于2025-09-04 15:30:14